Ahoy thar landlubbers

You need a special liscence to catch cray fish in England
As you must be able to decern between the native specie
(which are endangered) and the foreigne ones...

Love the magnet fishing idea.

It's easy, the american ones are fookin massive and bright blue, native ones are a bit smaller than your hand and purply-blackish. I think. Just eat the bright blue ones.